NHTSA complaint #11721327

Owner complaint summary

I am writing to report a significant safety issue associated with BMW vehicles equipped with the B58TU engine, particularly the 2019-2021 models. These vehicles feature an oil pump containing an internal plastic component responsible for regulating oil pressure. There have been numerous instances of this part fracturing in the field, leading to a sudden loss of oil pressure. The failure predominantly occurs during cold starts in low temperatures. When this occurs, oil pressure can fluctuate erratically or be lost completely, often with minimal warning. Potential warning signs include difficulties in electronically measuring the oil level, abnormal oil pressure readings, or sudden drivetrain malfunction alerts. These issues can escalate quickly, resulting in engine shutdown or severe damage due to oil starvation. This situation poses a serious risk, as the vehicle may become inoperable without warning while driving or immediately after startup. Such failures are particularly hazardous when vehicles become immobilized in traffic or during winter conditions, leaving occupants vulnerable to harsh temperatures while awaiting roadside assistance. The replacement of the oil pump necessitates extensive disassembly and typically incurs a cost of $6,000-$8,000, assuming no engine damage has occurred. A significant concern is that owners cannot easily ascertain whether their vehicle is equipped with the original plastic pump or a revised metal component. BMW's VIN-based parts lookup now indicates updated components even if the original plastic parts are still installed. Additionally, the original plastic part number has been removed from dealer networks. Failures have been reported across multiple production years, and the full extent of affected vehicles remains uncertain. Given that this condition can lead to abrupt vehicle disablement without adequate warning—especially in cold weather—this situation warrants investigation as a potential safety-related defect.